• Title/Summary/Keyword: Average Mutual Information

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Effect of a Finite Substrate Size on the Radiation Characteristics of Two-Element Linear E-plane Array Antennas (유한한 기판 크기가 2소자 E-평면 선형 배열 안테나의 방사 특성에 미치는 영향)

  • Yoon, Young-Min;Kim, Boo-Gyoun
    • Journal of the Institute of Electronics and Information Engineers
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    • v.49 no.12
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    • pp.95-110
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    • 2012
  • The effect of a finite substrate size on the radiation characteristics of a two-element linear E-plane array antenna using microstrip patch antennas is investigated. The average active element pattern characteristics of two-element E-plane array antennas printed on different dielectric constant substrates with various substrate sizes and element spacings are analyzed. Using the average active element pattern, the radiation pattern characteristics of the array antenna versus scan angle is analyzed. The simulation results show that the diffracted fields of surface waves from substrate edges have a significant effect on the radiation characteristics of a 2-element E-plane array antenna. The distance between the center of patch antenna and the substrate edges on the E-plane for the enhancement of radiation characteristics of the array antenna is about $0.35{\lambda}_0$.

Reducing the frequency of processor thrashing using guarantee/reservation in process migration (작업 이주시 보장/예약 기법을 이용한 프로세서 쓰레싱 빈도 감소)

  • Lee, Jun-Yeon;Im, Jae-Hyeon
    • The KIPS Transactions:PartA
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    • v.8A no.2
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    • pp.133-146
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    • 2001
  • In a dynamic load distribution policies, each node gathers the current system sates information before making a decision on load balancing. Load balancing policies based on this strategy can suffer from processor thrashing. In this paper, we propose a new algorithm which attempts to decrease the frequency of the processor thrashing, the algorithm is based on the integration of three components. The first, the algorithm of which determine the size of jobs be transferred. The second, negotiation protocol with obtains a mutual agreement between a sender and a receiver on the transferring job size. And the third, a symmetrically-initiated location policy. The algorithm proposed in this paper used Siman IV as simulation tool to prove the improvement of performance. I analyzed the result of simulation, and compared with related works. The mean response time shows that there are no difference with existing policy, but appear a outstanding improvement in high load. The thrashing coefficient that shows the average response time, CPU overhead and the thrashing ratio at both the receiving and sending node has been used in the analysis. A significant improvement in the average response time and the CPU overhead ratio was detected using our algorithm when an overhead occurred in the system over other algorithm. The thrashing coefficient differed in the sending node and the receiving node of the system. Using our algorithm, the thrashing coefficient at the sending node showed more improvement when there was an overhead in the system, proving to be more useful. Therefore, it can be concluded that the thrashing ratio can be reduce by properly setting the maximum and minimum value of the system’s threshold queue.

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A Folksonomy Ranking Framework: A Semantic Graph-based Approach (폭소노미 사이트를 위한 랭킹 프레임워크 설계: 시맨틱 그래프기반 접근)

  • Park, Hyun-Jung;Rho, Sang-Kyu
    • Asia pacific journal of information systems
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    • v.21 no.2
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    • pp.89-116
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    • 2011
  • In collaborative tagging systems such as Delicious.com and Flickr.com, users assign keywords or tags to their uploaded resources, such as bookmarks and pictures, for their future use or sharing purposes. The collection of resources and tags generated by a user is called a personomy, and the collection of all personomies constitutes the folksonomy. The most significant need of the folksonomy users Is to efficiently find useful resources or experts on specific topics. An excellent ranking algorithm would assign higher ranking to more useful resources or experts. What resources are considered useful In a folksonomic system? Does a standard superior to frequency or freshness exist? The resource recommended by more users with mere expertise should be worthy of attention. This ranking paradigm can be implemented through a graph-based ranking algorithm. Two well-known representatives of such a paradigm are Page Rank by Google and HITS(Hypertext Induced Topic Selection) by Kleinberg. Both Page Rank and HITS assign a higher evaluation score to pages linked to more higher-scored pages. HITS differs from PageRank in that it utilizes two kinds of scores: authority and hub scores. The ranking objects of these pages are limited to Web pages, whereas the ranking objects of a folksonomic system are somewhat heterogeneous(i.e., users, resources, and tags). Therefore, uniform application of the voting notion of PageRank and HITS based on the links to a folksonomy would be unreasonable, In a folksonomic system, each link corresponding to a property can have an opposite direction, depending on whether the property is an active or a passive voice. The current research stems from the Idea that a graph-based ranking algorithm could be applied to the folksonomic system using the concept of mutual Interactions between entitles, rather than the voting notion of PageRank or HITS. The concept of mutual interactions, proposed for ranking the Semantic Web resources, enables the calculation of importance scores of various resources unaffected by link directions. The weights of a property representing the mutual interaction between classes are assigned depending on the relative significance of the property to the resource importance of each class. This class-oriented approach is based on the fact that, in the Semantic Web, there are many heterogeneous classes; thus, applying a different appraisal standard for each class is more reasonable. This is similar to the evaluation method of humans, where different items are assigned specific weights, which are then summed up to determine the weighted average. We can check for missing properties more easily with this approach than with other predicate-oriented approaches. A user of a tagging system usually assigns more than one tags to the same resource, and there can be more than one tags with the same subjectivity and objectivity. In the case that many users assign similar tags to the same resource, grading the users differently depending on the assignment order becomes necessary. This idea comes from the studies in psychology wherein expertise involves the ability to select the most relevant information for achieving a goal. An expert should be someone who not only has a large collection of documents annotated with a particular tag, but also tends to add documents of high quality to his/her collections. Such documents are identified by the number, as well as the expertise, of users who have the same documents in their collections. In other words, there is a relationship of mutual reinforcement between the expertise of a user and the quality of a document. In addition, there is a need to rank entities related more closely to a certain entity. Considering the property of social media that ensures the popularity of a topic is temporary, recent data should have more weight than old data. We propose a comprehensive folksonomy ranking framework in which all these considerations are dealt with and that can be easily customized to each folksonomy site for ranking purposes. To examine the validity of our ranking algorithm and show the mechanism of adjusting property, time, and expertise weights, we first use a dataset designed for analyzing the effect of each ranking factor independently. We then show the ranking results of a real folksonomy site, with the ranking factors combined. Because the ground truth of a given dataset is not known when it comes to ranking, we inject simulated data whose ranking results can be predicted into the real dataset and compare the ranking results of our algorithm with that of a previous HITS-based algorithm. Our semantic ranking algorithm based on the concept of mutual interaction seems to be preferable to the HITS-based algorithm as a flexible folksonomy ranking framework. Some concrete points of difference are as follows. First, with the time concept applied to the property weights, our algorithm shows superior performance in lowering the scores of older data and raising the scores of newer data. Second, applying the time concept to the expertise weights, as well as to the property weights, our algorithm controls the conflicting influence of expertise weights and enhances overall consistency of time-valued ranking. The expertise weights of the previous study can act as an obstacle to the time-valued ranking because the number of followers increases as time goes on. Third, many new properties and classes can be included in our framework. The previous HITS-based algorithm, based on the voting notion, loses ground in the situation where the domain consists of more than two classes, or where other important properties, such as "sent through twitter" or "registered as a friend," are added to the domain. Forth, there is a big difference in the calculation time and memory use between the two kinds of algorithms. While the matrix multiplication of two matrices, has to be executed twice for the previous HITS-based algorithm, this is unnecessary with our algorithm. In our ranking framework, various folksonomy ranking policies can be expressed with the ranking factors combined and our approach can work, even if the folksonomy site is not implemented with Semantic Web languages. Above all, the time weight proposed in this paper will be applicable to various domains, including social media, where time value is considered important.

Job Stress and Its Related Factors in South Korean Doctors (일부 의사들의 직무스트레스와 관련 요인)

  • Kam, Sin;Lee, Sang-Won;Chun, Byung-Yeol;Yeh, Min-Hae;Kang, Yune-Sik
    • Journal of Preventive Medicine and Public Health
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    • v.34 no.2
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    • pp.141-148
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    • 2001
  • Objective : To investigate the sources, extent and related factors in South Korean doctors. Methods : The study subjects were 934 doctors in Taegu, Kyungpook Province, Korea(540 independent practitioners, 105 employed at hospitals and 289 residents in training). Information concerning job stress was obtained using a 9-item questionnaire. Information regarding related factors such as demographic characteristics(age, sex, marital status), perceptions on the socioeconomic status of doctors and working conditions(work time, on-call days per week) was also obtained by self-administered questionnaire during April and May, 2000. Results : Major sources of job stress included clnical responsibility/judgement factor, patient factor and work loading factor. The job stress score of residents was the highest among three groups. The score was lower in older doctors. The score was low among those who thought doctors' socioeconomic status was not good. The longer the work time, the higher the job stress score was. Multiple regression analysis was conducted to control for the mutual influence of independent variables. In regression analysis, the score of residents was higher than practitioners. Work time and socioeconomic status perception had negative effects on job stress score. Conclusion : The average job stress score of the doctors was high. Age, work type, working conditions and perceptions of socioeconomic status were found to besignificantly related to job stress score. Although the job stress of doctors is somewhat inevitable due to the nature of the doctor's job, control of work time, development of coping tools and other intervention methods are needed to reduce job stress of doctors. Further studies are required to understand the characteristics of iob stress and reduce the job stress of doctors.

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Efficient Authentication Establishment Scheme between IoT Device based on Pascal Triangle Theory (파스칼 삼각 이론 기반의 IoT 장치간 효율적인 인증 설립 기법)

  • Han, Kun-Hee;Jeong, Yoon-Su
    • Journal of the Korea Convergence Society
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    • v.8 no.7
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    • pp.15-21
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    • 2017
  • Recently, users' interest in IoT related products is increasing as the 4th industrial revolution has become social. The types and functions of sensors used in IoT devices are becoming increasingly diverse, and mutual authentication technology of IoT devices is required. In this paper, we propose an efficient double signature authentication scheme using Pascal's triangle theory so that different types of IoT devices can operate smoothly with each other. The proposed scheme divides the authentication path between IoT devices into two (main path and auxiliary path) to guarantee authentication and integrity of the IoT device. In addition, the proposed scheme is suitable for IoT devices that require a small capacity because they generate keys so that additional encryption algorithms are unnecessary when authenticating IoT devices. As a result of the performance evaluation, the delay time of the IoT device is improved by 6.9% and the overhead is 11.1% lower than that of the existing technique. The throughput of IoT devices was improved by an average of 12.5% over the existing techniques.

Adaptively Compensated-Disparity Prediction Scheme for Stereo Image Compression and Reconstruction (스테레오 영상 압축 및 복원을 위한 적응적 변이보상 예측기법)

  • 배경훈;김은수
    • The Journal of Korean Institute of Communications and Information Sciences
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    • v.27 no.7A
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    • pp.676-682
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    • 2002
  • In this paper, an effective stereo image compression and reconstruction technique using a new adaptively compensated-disparity prediction scheme is proposed. That is, by adaptively predicting the mutual correlation between the stereo image using the proposed method, the bandwidth of the stereo input image can be compressed to the level of the conventional 2D image and the predicted image also can be effectively reconstructed using this transmitted reference image and disparity data in the receiver. Especially, in the proposed method, once the feature values are extracted from the input stereo image, then the matching window size for the predicted image reconstruction is adaptively selected in accordance with the magnitude of this feature values. From this adaptive disparity estimation method, reduction of the mismatching probability of the disparity vectors is expected and as a result, the image quality in the reconstructed image can be improved. In addition, from some experiments using the CCETT's stereo images of 'Fichier', 'Manege' and 'Tunnel', it is shown that the proposed method improves the PSNR of the reconstructed image to about 9.08 dB on average by comparing with that of the conventional methods. And also, it is found that there is almost no difference between the original image and the predicted image reconstructed through the proposed method by comparison to that of the conventional methods.

A study on the current status and ways of activating 3PL (제3자물류의 실태분석 및 활성화 방안에 관한 연구)

  • 이충규;김준석
    • Journal of Korea Port Economic Association
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    • v.18 no.2
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    • pp.65-90
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    • 2002
  • Despite the importance and necessity, the 3PL has not been activated to date. Among many views, customers claim that logistics service provider(LSP) are not prepared or capable of offering satisfactory 3PL services, while LSP emphasize the lack of mutual trust, closed corporate culture of the customer and excessive demand for reducing the costs. With this keeping in mind, it surveyed difference of perception between users and providers of 3PL services in terms of the actual status of using 3PL services, the degree of satisfaction and key factors for selecting 3PL provider through the questionnaire. As shown in this study, 43.3% of the respondents outsourced logistics services. However, Most company outsourced only inland transportation (49.5%) which is a simple and limited scope of 3PL services, but it also indicated that the percentage of users have ranged was less then 10% in outsourcing their whole logistics sector to 3PL provider and employing other logistics functions. Among respondents, a majority of the service provider stated that they offered satisfactory cost-saving to the customers, while users felt that the degree of satisfaction for using 3PL services was evaluated as at an average level and they more highly regarded the strong partnership of their 3PL provider rather than the saving of cost and improvement of customer's services. Moreover, in contrast to the 3PL providers which regard the most important factor for selecting 3PL service provider is the logistics cost quoted, users of 3PL services felt that the quality of services was more significant than the reduction of cost, and this tendency for selecting 3PL providers was shown in more advanced countries. While users of 3PL services indicated that the main reason for not using 3PL services was to avoid disclosing information of their business and it costs much for employing 3PL providers than doing themselves, 3PL providers thought it was due to reluctancy of opening information and resistance from the logistics division engaged in logistics activities concerned. Accordingly, providers and users of 3PL services should trust each other and prepare plan to activate 3PL services under the collaborative relationships as soon as possible.

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Mutual interference suppression of the sinusoidal frequency modulated pulse using SHAPE algorithm (SHAPE 알고리즘을 이용한 사인파 주파수 변조 펄스의 상호간섭 억제)

  • Kim, Guenhwan;Lee, Donghwa
    • Journal of Korea Society of Industrial Information Systems
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    • v.27 no.5
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    • pp.49-59
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    • 2022
  • The SHAPE algorithm has the advantage of being able to shape the pulse spectrum as desired and design it not to distort other characteristics, so it was used in the active sonar pulse design. In this paper, we propose a pulse design using the SHAPE algorithm for a multi-static sonar system to reduce the cross-correlation between frequency-adjacent pulses and prevent the performance degradation of the pulses themselves. The boundary function of the SHAPE algorithm is set to be limited to the pulse bandwidth. As a result of applying the proposed design method to the sinusoidal frequency modulated pulse, the peak cross-correlation level (PCCL), which means the degree of cross-correlation, was reduced by 44.23 dB. Although the PCCL decreased by several tens of dB, no significant change in the ambiguity function was observed, and the integrated sidelobe level (ISL), which means the average value of the side lobe, increased by 11.64 dB.

Analysis of Collection and Loan Usages in Small-sized University Libraries (소규모 대학도서관의 장서 대출 이용 현황 분석)

  • Hee Jin Kim;Eungyung Park
    • Journal of Korean Library and Information Science Society
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    • v.54 no.4
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    • pp.1-24
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    • 2023
  • In a situation with reducing numbers of students and local universities in crisis, this study aims to analyze collection and loan usage data in small-sized university libraries and present evidence for guiding their collection development policy. The data was collected from Rinfo from 2010 to 2022 regarding the numbers of enrolled students, collected books, book loans, and electronic resources and compared the average values of entire 4-year university libraries to those of small-sized ones by year and region. Results show that while the numbers of enrolled students and book loans have decreased in both of groups, the number of collected books has increased 30% more in small groups and the amount of electronic resource use has increased enormously as well. Correlation analysis presents that both of groups have the consistent result. It is suggested that small-sized university libraries should highly increase their budget ratio to electronic resources for collection development and build a consortium by university's speciality for mutual use of electronic resources.

A Study of the Abilities of House-keeping of Korean Female Students (한국여자대학생의 가사능력에 관한 연구)

  • 박인덕
    • Journal of the Korean Home Economics Association
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    • v.11 no.4
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    • pp.399-413
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    • 1973
  • A Study of the Abilities of House-keeping of Korean Female Students. We tend to have much trouble in doing house-keeping with the lack of practical experience in our daily life in this age of information because we learn more things by vicarious experiences with the help of communication media such as radio, T.V. The purpose of this study is to contribute to the education of house-keeping and teaching of home economics which are essential to female students who will become good house-wives and good members of families. In this thesis, the fundamental items of every day life such as food, costume, and home management were made out in a questionnaire with a view to evaluating the abilities of students' house keeping by these data. A random sample was taken composing of juniors and seniors with the sample size, n = 581, out of the universities and Colleges in Korea ; i.e., Yonsei Univ., Korea Univ., Ewha Univ., Sukmyong Univ., Sung Shim Womans' College (at choon chun), Duk Sung Womans' College, etc. It is to be noted that home economics majors were excluded. The results are as follows 1. Out of the total 25 fundamental items about food the average ability in the case of "I can" is only 11 items, "I have experience" 7 items, and "I have no experience" 7 items. 2. Out of the total 20 fundamental items about costume the average ability, in the case of "I can" is 4 items, and "I have experience" 8 items, and "I have no experience" 8 items. 3. Out of the total 20 fundamental items about home management, the average ability, in the case of "I can" is 5-items. "I have experienc" 8-items, and "I have no experience" 6-items. The following conclusions have been reached on the basis of the above survey : a) On the whole students are poorest at practical house-keeping. b) It is to be pointed our that female students have little experience to participate in practical house keeping every daily life c) Female students are apt to have the self-confidence that they can carry on the house-keeping well. d) One may emphasize the point which tends to be neglected in home-education : each house wife should have the ability of practical house-keeping, mutual under-standing among family members, a sense of responsibility, coorperation and services as a good member of family.

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